Modern digital hearing devices are very complex little things. Effectively a miniature computer, the devices sample sounds up to 20,000 per second to quantify what sounds are happening around you.
Using this information, the computer chip can then analyse the incoming signal. Differentiating between speech, noise, music, wind, etc. the devices can change the way in which they work to give you the best speech intelligibility, whilst maintaining maximum comfort.
There are several ways in which this is achieved, but simply put this can be categorized by a few concepts:
- Directional Microphones (the ability to focus attention on the sounds that matter)
- Speech Extraction (separating a speech signal from surrounding noise)
- Wind Noise Reduction (reducing annoying buffeting of wind on the microphones)
- Impulse Noise Reduction (recognising and suppressing sharp sounds such as cutlery or crockery)
These and other systems working behind the scenes attempt to provide you with the most comfortable and natural listening experience possible. The cost of hearing devices is determined by how effective each of these factors are, or if they are available at all.